This invention relates generally to sunroof assemblies for automotive vehicles and specifically to a drive mechanism used to operate a sunroof assembly.
It is common knowledge to provide a single sunroof within a stationary roof of an automotive vehicle. These traditional sunroofs typically employ a transparent glass pane slidable from a covering position, somewhat flush to the roof, to a retracted position, which allows sunlight and ventilation access through an opening within the roof. Another traditional sunroof construction provides a transparent glass pane which is tiltable from a closed position to a pivoted venting position. This allows air from within the vehicle to pass through an opening created between the vented pane and the roof. A single sliding interior sunshade has also been employed with various of these sunroofs. Such sunshade are typically horizontally oriented and slidably movable to expose or cover a sunroof. Exemplary U.S. patents disclosing driving mechanisms for operating these conventional sunroofs are as follows: U.S. Pat. No. 5,069,501 entitled "Spoiler Sunroof Control Mechanism" which issued to Baldwin et al. on Dec. 3, 1991; U.S. Pat. No. 5,026,113 entitled "Sliding and Venting Sunroof" which issued to DiCarlo et al. on Jun. 25, 1991; and U.S. Pat. No. 4,537,442 entitled "Sliding and Tilting Roof for Motor Vehicles" which issued to Jardin on Aug. 27, 1985.
U.S. Pat. No. 4,786,102 entitled "Sun Roof Apparatus of Vehicle Roof" which issued to Sakamoto et al. on Nov. 22, 1988, attempts to further increase the effective roof opening, especially above the front seat, by employing a pair of movable covering panels. This device provides a rear cover panel which is detachably removable such that a front cover panel can be rearwardly slid. Provisions are also made for manually mounting the removed rear cover panel upon the retracted front cover panel. However, this system appears ungainly to operate especially while driving the automobile.
U.S. Pat. No. 5,197,779 entitled "Power Sliding Sunroof" which issued to Mizuno et al. on Mar. 30, 1993, discloses a pair of slidable sunroofs mounted in tracks on top of a stationary roof. However, this non-flush roof system is aesthetically prominent, is prone to excessive wind noise during vehicle driving and will cause excessive aerodynamic drag in all operating positions. It should be noted that conventional driving mechanisms require complicated and delicate lockout mechanisms for dictating desired cam follower and camming slot interactions. For instance, U.S. Pat. No. 5,197,779 requires a swingable hook (54) and U.S. Pat. No. 5,069,501 requires a pivoting stop member (78).
In accordance with the present invention, the preferred embodiment of a drive mechanism for an automotive vehicle sunroof assembly employs a moving cam and a stationary cam, both of which are engaged by a sunroof pane supporting carriage with cam followers. The specific camming surfaces cause the carriage and pane to move between closed, vent and open positions. In another aspect of the present invention a shoe of the carriage is limited to generally horizontal movement along a track. In a further aspect of the present invention, a latch is provided on the moving cam for engagement with a striker movable with the pane. An additional aspect of the present provides an L-shaped camming surface within the stationary cam. In yet another aspect of the present invention, the sunroof drive mechanism employs a pair of sunroofs movable in response to placement of moving cams in relation to stationary cams. In still another embodiment, a H-shaped sunroof tub is used. A method of operating a sunroof assembly is also disclosed.
The sunroof drive mechanism of the present invention provides many advantages over conventional sunroof constructions. For example, the present invention sunroof drive mechanism eliminates the need for the traditional complicated cam lockout mechanism. Thus, the present invention achieves a more robust, cost effective, durable and reliable camming system. Furthermore, various embodiments of the present invention eliminate the need for a costly electronic control unit. Moreover, the sunroof drive mechanism of the present invention provides a less complicated design by removing the need for the many traditional linkages and moving parts. Additional advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.